This invention relates to a radiological examination table equipped with an apparatus for positioning and displacing a patient.
Present radiological examination tables make possible the shifting of the patient by means of different motions imparted to its patient-supporting platform in the longitudinal and lateral sense of the platform.
The presence of a motor means (motor, reduction gears and motion transfer members) makes it necessary that one or both ends of the patient-supporting platform, which are opaque to radiation, extend over a certain considerable length.
Futhermore, in cases of machines which have both longitudinal and lateral movement, an intermediate frame, which is subjected only to one of those two movements and which carries the driving assembly for the other movement, must be present.
This intermediate frame, aside from the manufacturing complications which it requires, has the distinct disadvantage, because of its thickness, of increasing the distance between the support plane of the patient and the film in the associated casssett or in a film handling device for bare film, when the latter is in the X-ray exposure field, in the case where there is a remotely controlled apparatus carrying the cassette receiver of the radiographic pictures below the patient-supporting platform.
Consequently, presently known tables have a certain number of disadvantages and are to some degree inconvenient. These tables could be advantageously improved, especially with respect to the possibilities of shifting or displacing the patient. Actually, especially with respect to longitudinal and lateral movements of a patient with respect to the examining assembly, it would be very desirable in the case of universal, remotely controlled tables, to be able to impart to the patient two other possibilities of motion, i.e. (1) a movement changing the height of the plane of the patient-supporting platform, and (2) an arcuate movement of the patient in the transverse sense.
In the case of a universal, remotely controlled apparatus equipped with a device for tomography, the desired height-changing movement permits the choice of the height of the layer of the patient's body (this layer being parallel to the plane of the film and traversed by the axis about which both the X-ray source and the film are moved in opposite directions) which is necessary for tomographic examination. It also readily permits use of techniques for optical magnification.
The arcuate movement is, from the medical point of view, very desirable because it permits changing the direction of force due to gravity with respect to the various organs in the patient's body. Consequently, it is made easy to study the movement and displacement of injected contrast materials, which may be either lighter or heavier than the region of the patient's body into which these materials have been injected.
Until the present time, this desirable arcuate movement has been achieved by a special mechanism which is independent of those which powered the other movements of the patent-supporting platform.